dt-bindings: clock: samsung: convert Exynos5250 to dtschema

Convert Samsung Exynos5250 clock controller bindings to DT schema format
using json-schema.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20210825134056.219884-2-krzysztof.kozlowski@canonical.com


Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>